Drill bit



R. G. PETER Aug. 21, 1956 DRILL BIT 2 Sheets-Sheet 1 Filed Sept. 12.1952 Rob 6/" Z 6. Fe fer dy;

INVENTOR ATTOR/VEVJ Aug. 21, 1956 R. G. PETER 2,759,706

DRILL BIT Filed Sept. 12, 1952 2 Sheets-Sheet 2 Robe/"2 6. Fe 2 erINVENTOR.

ATTORNfVJ United States Patent 2,759,706 DRILL BIT Robert G. Peter,Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., acorporation of Tex-as Application September 12', 1952, Serial No.309,259

2 Claims. (Cl. 255-845.)

This invention relates generally to drill bits and more particularly torotary drill bit rollers.

A general object of this invention is to provide a rotary drill bitadapted to drill earth formations faster and more efficiently.

It is anobjeet of this invention to provide a new and improved rotarydrill bit roller having teeth thereon which are relatively widely spacedand arranged in such a manner to provide good rolling action of theroller on the bottom of the hole being drilled by the drill bit.

Another object is'to provide a new and improved rotary drill bit rollerhaving teeth thereon which are relatively widely spaced and arranged toprovide adequate tooth area to remove efliciently the formation from theouter gage portion of the bore hole being drilled.

Another object is to provide a new and improved drill bit roller thatwill not readily pack or ball up with cuttings dislodged during thedrilling operation.

Another object is to provide a new and improved drill bit roller thatmay be readily cleaned, of cuttings adhering thereto, by the flushingaction of drilling fluid customarily circulated during the drillingoperation.

Other objects and advantages will become apparent from the followingdescription and accompanying drawings wherein, by way of illustration,an embodiment of this invention is set forth.

In the drawings:

Fig. 1 is a side elevation view of a cross roller type drill bit.

Fig. 2 is a side elevation view taken on line 2-2 of Fig. 1.

Fig. 3 is an isometric view of a side roller showing the arrangement ofthe teeth thereon.

Fig. 4 is a detail view of a side roller showing the arrangement of theteeth thereon.

Fig. 5 is a sectional view taken on line 5-5 of Fig. 4.

Referring to Figs. 1 and 2, the bit head is indicated at 1. It may beprovided with the usual threaded shank 2 for attachment to a drill stem(not shown). The head 1 has a pair of oppositely disposed dependingcross roller bearing extensions 3 on which are rotatably mounted crossrollers 4. The head 1 also has a pair of oppositely disposed dependingside roller bearing extensions 5 on which are rotatably mounted siderollers 6. The head 1 also has disposed therein a drilling fluid nozzle7 so that drilling fluid pumped downwardly through the drill stem (notshown) may pass through the nozzle 7 to be discharged toward the bottomof the hole in the usual manner.

Rotary drill bits now in common use may embody a bit head havingfrusto-conical cross rollers and side, or gage rollers rotatably mountedin the lower portion thereof. The bit head may be connected to the endof a drill stem and lowered to the bottom of the hole being drilled. Thedrill stem is rotated to cause the rollers to roll upon the bottom ofthe hole and thereby cut or crush the formation being drilled. Adrilling fluid is pumped downor gage, roller 6 may be clearly seen.

ice,

wardly through the" drill stem and: through: a drilling fluid nozzle inthe bit-head, and upwardly in the space between the drill stem and thewall of the hole to the surface of the earth. One of the most importantdesired functions; of the drilling fiuiti'thus circulating is' to removequickly the cut or crushedparticles of formation from the bottom of thehole and from use rollers and adjacent arts of th bit. This function isnot always efiicieritly performed, because iii some formations,particularly in the relatively sea, sticky shale formations, theparticlesand cuttings may adhere t6 and peer between the roller teethand adjacent parts of the hides a result, the pene-' tration of theroller teeth into the fornication may be i111 ped'ed and the rollerBecome so packed or bailed up that the rollers may not rotate pro erlyand may be worn by skidding up'tiit the team of the hole; therebyreducing the useful life of the bit. 7 I

It will be apparent that if the roller teeth were widely spaced, thetendency of the cuttings to pack and adhere between the roller teethwould be alleviated; however, merely to reduce the-number of teeth on" aconventional type roller may not be practical since the teeth may becometoo widely spaced angularly, and the roller may skid rather than turnabout its axis as the drill bit is rotated on the bottom of the borehole. Also, as the teeth become more widely spaced around a side or gageroller, there is a corresponding reduction in the tooth area at theouter or gage portion of the roller. The function of the gage portion ofthe roller is to maintain a full gage bore hole so that subsequent drillbits will not have to ream the bore hole to reach the bottom thereof;therefore, it is important to provide adequate gage cutting tooth areaon side rollers to maintain the gage of the hole being drilled. In myinvention, I provide a new and improved drill bit roller havingrelatively widely spaced teeth, to alleviate the packing thereof withcuttings dislodged during the drilling operation. The roller also hasadequate tooth area to drill the outer or gage portion of the hole beingdrilled, and has good rolling action on the bottom of the bore hole.

In Figs. 3, 4 and 5 the tooth arrangement on the side, The roller 6 hasan outer gage portion 8 and an inner end 9. The roller 6 has a pluralityof circumferential, or annular, gage cutting teeth 10 disposed along theouter gage portion 8, and a plurality of axial, or longitudinallyextending, teeth 11 disposed between the circumferential teeth 10, andextending from the outer gage portion 8 to the inner end 9 of the roller6: The teeth 10 and 11 are disposed upon a peripheral tooth bearingportion as shown in Figure 3. The teeth 10 occupy only that portion ofthe transverse portion of the tooth bearing portion between the innerand outer gage portions which is adjacent to the outer gage portions 8,thereby leaving that portion 12 of said transverse portion adjacent tothe said inner end portion 9 unoccupied by teeth. This tooth arrangementaffords the wide area 12 between the teeth thus reducing the possibilityof cuttings packing therebetween, and aifords better cleaning of theroller 6 by the flushing action of the drilling fluid being circulatedas above described.

The circumferential teeth 10 are along, and the outer ends of the teeth11 extend to, the outer gage portion 8 of the roller 6, therebyproviding adequate tooth area to drill the outer or gage portion of thebore hole.

The angular spacing between the circumferential teeth 10 and the axialteeth 11 at the outer gage portion 8 of the roller 6 is relativelyclose, thus affording good rolling action due to the teeth 11 of theroller on the bottom of the hole being drilled by the drill bit.

The foregoing disclosure and description is illustrative of theinvention, and is not to be limited to the embodiment shown. Variouschanges, within the scope of the following claims, will occur to thoseskilled in the art.

I claim: Y

1. A drill bit comprising a bit head, cross rollers and gage rollersrotatably mounted in the lower portion thereof. each of the said gagerollers being annular in form, the opposite spaced side faces thereofdefining an inner end portion and an outer gage portion and a pcripheraltooth bearing portion, said tooth bearing portion havingcircumferentially spaced teeth thereon, the cutting edges thereof beingtransverse 'to said tooth bearing portion and extending throughout thewidth thereof, and a row of circumferentially spaced teeth having thecutting edges thereof in the plane of the roller extending circularly ofthe roller and occupying only that portion of the transverse portion ofthe tooth bearing portion between the inner and outer gage portionswhich is adjacent to the said outer gage portion and alternating withsaid first mentioned teeth thereby leaving that portion of saidtransverse portion adjacent to the said inner end portion unoccupied byteeth, and adapted to drill only the outer gage portion of the formationof the bore hole being drilled.

2. A drill bit gage roller annular in form, the opposite spaced sidefaces thereof defining an inner end portion and an outer gage portionand a peripheral tooth bearing portion, said tooth bearing portionhaving circumferentially spaced teeth thereon, the cutting edges thereofbeing transverse to said tooth bearing portion and extending throughoutthe width thereof, and a row of circumferentially spaced teeth havingthe cutting edges thereof in the plane of the roller extendingcircularly of the roller and occupying only that portion of thetransverse portion of the tooth bearing portion between the inner andouter gage portions which is adjacent to the said outer gage portion andalternating with said first mentioned teeth thereby leaving that portionof said transverse portion adjacent to the said inner end portionunoccupied by teeth.

References Cited in the file of this patent UNITED STATES PATENTS1,656,022 Scott Jan. 10, 1928 2,117,679 Reed May 17, 1938 2,132,498Smith et al. Oct. 11, 1938 2,165,584 Smith et al. July 11, 19392,363,202 Scott Nov. 21, 1944

